Overdraft key-locking and indicating mechanism for calculating machines



Sept. 9 1924.

F. w. BERNAU OVERDHAFT KEY LOCKING AND INDICATING MECHANISM FOR CALCULATING MACHINES GER 0 $5. $5

Se t. 9, 1924. 1,508,267

F. W. BERNAU OVERDRAFT KEY LOCKING AND INDICATING MECHANISM FDR CALCULATING MACHINES Original Filed Oct. V1, 1922 13 Sheets-Sheet 2 7 R6 uvww Sept. 9 1924.

F. w. BERNAU UVERDRAFT KEY LOCKING AND INDICATINQ MECHANISM FOR CALCULATING MACHINES 31, 1922 13 Sheets-Sheet 5 Original Filed Oct.

Sept. 9, 1924.

F. w. BERNAU ovaanmm KEY LOCKING AND mnxcnzus macnmrsu FOR CALCULATING mcmuss Original Filed Oct. 31, 1922 13 Sheets-Sheet 4 mentor,

OVERDRAFT KEY LOCKING AND INDICATING MECHANISM FOR CALCULATING MACHINES Original Filed Oct. 31, 1922 1: Sheets-Sheet '5 smeeee Sept. 9, 1924. 1,508,267

F. W. BERNAU OVERDRAFT KEY LOCKING AND INDICATING MECHANISM FOR CALCULATING MACHINES Original Filed Oct. 31' 1922 13 Sheets-Sheet 6 Sept. 9 1924.

F. w. BERNAU ovsnoamr KEY LOCKING AND mmcume mscumxsu FOR CALCULATING MACHINES Original Filed Oct. 31, 1922 13 Sheets-Sheet 7 Sept. 9, 1924.

F. W. BERNAU OVBRDHAFT KEY LOCKING AND INDICATING MECHANISM FDR CALCULATING MACHINES Original Filed Oct. 31, 1922 13 Sheets-Sheet 8 Se t. 9, 1924. 1,508,267

F. w. BERNAU OVERDRAFT KEY LOCKING AND INDICA'IING MECHANISM FOR CALCULATING MACHINES Original Filed Oct. 31. 1922 13 Sheets-Sheet 9 T l l l i i, l L.

Sept. 9 1924. 1,508,267

F. w. BERNAU OVERDHAFT KEY LOCKING AND INDICATING MECHANISM FOR CALCULATING MACHINES Original Filed Ocfc. 31, 1922 13 Sheets-Sheet 10 Sept. 9 1924.

F. w. BERNAU OVERDRAFT KEY LOCKING AND INDICATING MECHANISM FOR CALCULATING MACHINES Original Filed Oct. 31. 1922 1a Sheets-Sheet 11 Sept. 9, 1924.

F. W. BERNAU ovsammm may LOCKING AND, mmcnmc, MECHANISM FOR cucum'rme umcamas Original Filed Oct.

31. 1922 13 Sheets-Sheet l2 Sept. 9 1924.

F. W. BERNAU OVERDRAFT KEY LOCKING AND INDICATING MECHANISM FOR CALCULATING MACHINES l3 Sheets-Sheet 1 3 Patented Sept. 9, 1924.

UNITED STATES PATENT OFFICE.

FREDERICK W. BERNAU, 0F HILLSIDE, NEW JERSEY. ASSIGNOR TO ELLIS ADDING TYPEWRITE'R COMPANY, OF NEWARK, NEW JERSEY, A. CORPORATION OF NEW JERSEY.

OVERDRAFT KEY-LOCKING AND INDICATING MECHANISM FOR CAIJCiULATING MACHINES.

Original application filed October 31, 1922, Serial No. 598,155. Divided and this application filed June 4. 1924. Serial No. 717,782.

To all whom it may concern:

Be it known that I, FREDERICK W. BERNAU, a citizen of the United States, residing at Hillside, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Overdraft Key-Locking and Indicating Mecha-- nism for Calculating Machines, of which the following is a specification.

The present application is a division of Serial No. 598,155, filed October 31, 1922.

This invention relates to calculating machines which are adapted for performing addition and subtraction, and, if desired, for listing numbers and for printing the results of addition and subtraction carried on by the machine.

My present improvements are particularly intended for use in connection with the mechanisms of the well known Ellis printing calculating machine, especially the mechanism'set forth in patents to Halcolm Ellis No. 1,065.792, June 24, 1913, Total signal device; No. 1,197,276, September 5, 1916, Combined adding machineand t pewriter; and No. 1,203,863, November 7, i916, Mechanical calculator.

It is to be understood, however, that the present improvements and the principles involved therein are not, necessarily, restricted to embodiment in mechanism similar to the Ellis machine as these improvements may be used in other calculating machines and the claims are to be understood as covering any improvements involving the principles of the invention in whatever calculating machine they may be employed.

However, to afford a clear understanding of the different mechanisms involved in the present invention, they are hereinafter described, and are shown in the accompanying drawings, in connection with so much of the mechanism of the Ellis machine, particularly as disclosed in Patents Nos. 1,065,792,

' 1,197,276 and 1,203,863, as will afford a clear understanding of the constructions, operations, functions and principles involved in the invention.

There are certain classes of work which a calculating machine is required to handle,

demanding notice to the operator that the debit items accumulated exceed the credit items; depositors accounts in a bank constitute a class' of work wherein such notification is important because an account in that condition is overdrawn. Furthermore, it is important that a calculating machine not only signal the fact that an account is overdrawn but also enable the operator to determine the amount of the overdraft and to print on the ledger sheet being handled by the machine the amount the account is overdrawn or the complement of that amount and to so print the figures or identify them that they will be prominently displayed on the sheet and on carbon copies thereof.

The signal provided by the present invention for the purpose of informing the operator that anroverdraft is present in the accumulator and that the account being handled by the machine is overdrawn, comprises means adapted to automatically lock the balance or total key or keys when this condition is present. lVhen the operator attempts to depress the balance or total key or keys, the locked condition thereof is notification that the accumulator contains an overdraft.

Therefore, when attempt is made to take the balance, and it is found that an over.- draft exists, it becomes necessary for the operator to manually restore the key-locking mechanism to normal, released, condition in order that the machine may be operated.

To enable this to be done, the locking mechanism is coordinated with the decimal slide of the Ellis machine, such slide being disclosed in Patent No. 1,197,276, in such manner that on operating the slide the locking mechanism will be released so that the machine can be operated.

An overdraft is an important and abnormal condition, and it is desirable that it be printed in a distinguishing manner so that it will be easily picked out bythe eye. To that end, novel means is provided for printing the item representing an overdraft in a distinguishing fashion, as in a different color, for instance red, and, also, identified by a sign so that the item will be marked in a distinguishing manner on any carbon copies, such distinguishing printing occurrin on the next operation of the machine after the lock has been released as that op eration causes printing of the overdraft item. The operation of printing an overdraft item in a distinguishing color may be carried out by employing a bichrome inked ribbon, and ribbon vibrator therefor, and combining therewith novel means which is automatically set so that when the machine operates after the release of the lock or looks, the ribbon vibrator or shift will be moved for that one operation a sufiicient distance to bring the differently colored, say red, sec-v tion of the ribbon in line with the printing type so that a red impression Will be made when the item is pririted, the mechanism immediately thereafter being restored to its normal condition so that succeeding items will be printed in the usual color.

Identification of an overdraft item is accomplished by employing means for automatically printing the overdraft item with a distinguishing mark or sign. *Vhen this means is employed the same item is identified not only on the original ledger sheet but also on all carbon copies being made.

Identification of an overdraft item by printing it with a distinguishing characteristic may, according to my invention, be had by printing the item in a different color, or, accompanied by a sign or signal,- or both methods may be used simultaneously.

The Ellis Patent No. 1,203,863, dated November 7, 1916, provides a subtraction key in addition to the usual controlling keys of the Ellis machine; furthermore, both of the accumulators of the duplex calculator shown in that patent are adapted for the performance of either addition or subtraction.

In the present invention I prefer to have one of the accumulators adapted for both addition and subtraction, as with the accumulators of the machine of the Ellis Patent No. 1,203,863, and to have the other accumulator a straight adding accumulator. The straight adding accumulator may be ofthe construction set forth in my a plication filed October 24, 1921, Serial l\o. 510,029.

It is to be understood, however, that both of the accumulators employed in connection with the present improvements may be adapted for both addition and subtraction as, for instance, in Ellis Patent No. 1,203,863.

While the subtraction key may be otherwise-arranged, I prefer to substitute it for one of the controlling keys, for instance, the Dr. sub-total key. Of the other controlling keys of the Ellis machine, the sub-total and total keys may be suitably labeled to represent the total deposits and the bal- .Jator.

lance", respectively, and another of the keys may be labeled to represent the total checks, to particularly adapt the machine for use in bank work.

As described and shown, the subtraction key of the present machine is adapted to become automatically restored after the machine has gone through its cycle of operation, making it necessary for the operator to hold down the subtraction key by the finger if a series of subtracting operations are to be carried on consecutively but as it is a simple matter to provide latching means for holding down the subtraction key, when it is desired to carry on a series of subtracting operations, it is to be understood that such latch may be used. In ordinary bank accounting, it is generally inadvisable to provide means for latching the subtracting key as this opens the way for forgetfulness on the part of the operator which would result in improper operation in that class of work.

Combined with the substracting key is ,special mechanism, substituted for certain of the pieces, cams, and levers of the machine of Ellis Patent No. 1,203,863 and, additional thereto, a link and a special hook or pawl by which the parts are conditioned so that the accumulator is brought into a condition by which it will perform subtraction on the next operation of the machine. It is to be understod that the foregoing mechanism does not interfere with the carrying on of addition in the straight adding accumulator as if both adding and subtracting accumulator and straight adding accumulator are employed, subtraction can be carried on in one accumulator while addition is being performed in the other accumu- Furthermore, a total can be taken from one accumulator, the amount of which may be subtracted from the accumulation of the remaining accumulator.

The overdraft mechanism by which the lock or locks or signal or signals heretofore referred to are operated and other mechanisms are set, is under the control of the subtracting pawl or hook of the highest order of the adding and subtracting accumulator. The subtracting pawl 01- hook itself is of the same construction as the cormentioned Ellis patents for a full disclosure of all mechanisms and their operations which are directly or indirectly related to the said improvements and in the following description and accompanying drawings reference is made to only so much of the patented Ellis machine as will afford a clear understanding of the relationship of the present improvements thereto.

I am aware that modifications may be re sorted to in carrying out the essential principles of the various improvements herein before outlined and which are hereinafter specifically described and are shown in the accompanying drawings. It is to be understood, therefore, that the constructions specifically described and shown, while the preferred embodiments of the invention as at present devised by me, are susceptible of modification in many respects without departing from the essential principles thereof.

In the accompanying drawings:

Figure 1 is an elevation of the left hand side of the machine showing only so much of the mechanisms of the patented Ellis machine as will afford a clear understanding of such of the present improvements as directly relate to the subtracting key, which is in depressed position, mechanism for controlling the upper adding and subtracting accumulator, and the overdraft locks for the balance and total deposits keys or total and sub-total keys, the keys" illustrated being in normal. position.

Fig. 2 is a view similar to Fig. 1, the total or balance key and the sub-total or total de posits keys being locked by the overdraft mechanism, an overdrafthaving previously occurred.

Fig. 3 is an elevation at the right hand side of the machine, the parts being shown in normal position; certain parts being omitted.

Fig. 4 is a plan view thereof, certain parts being omitted.

Fig. 5 is a view similar to Fig. 3, the set link having been moved to the right by the manipulation of the decimal slide. the tabulating hook being in normal position, and the tabnlating control lever being in position to prevent automatic tabulation.

Fig. 6 is a similar view. the tabulating hook having risen and being prevented from operating the tabulating mechanism by the control lever. the parts being as they appear at the end of the forward stroke of the operating shaft.

Fig. 7 is a plan view of the parts when in the position shown in Fig. 5.

Fig. 8 is a perspective view. the side frames of the machine being in dotted lines, showing the overdraft mechanism and 0perative connections to the locks for the l1alance or total, and total deposits or sub-total key, the ribbon shifting mechanism and decimal slide, various mechanisms of the machine being omitted for the sake of clearness and the overdraft mechanism and locks being in normal position.

Fig. 9 is a part side elevation and part sectional view showing certain of the mechanisms at the ri ht hand side of the machine, and, also, t e'overdraft mechanism at the left hand side of the machine, the shift bar of the accumulator being set for addition and the overdraft mechanism and ribbon mechanism being in normal condition.

Fig. 10 isa rearelevation of the machine showing the overdraft shaft and certain of the devices related thereto.

Fig. 11 is a plan-view of the overdraft mechanism, ribbon mechanism and links or bars that control the locks, the decimal slide being shown-as having been moved toward the left, the front'part of the machine and various mechanisms being omitted.

Fig. 12 is a partly sectional, partly elevational, detail View of the overdraft mechanism as set for carrying on a subtracting operation, before an overdraft has taken place.

Fig. 13 is a similar view showing the posi' tion of the parts after an overdraft has occurred.

Fig. 14 is a' detail side elevation of the ribbon shift mechanism when in normal position for causing ordinary printing, say in black, to occur.

Fig. 15 is a similar view showing the mechanism arranged so that the ribbon vibrator will be shifted to cause printing in a distinctive color, say red, as when an overdraft has taken place.

Fig. 16 is a front view of the decimal slide shown in its extreme right hand position.

Fig. 17 is a side elevation of mechanism for automatically printing identifying signs or signals, the parts being in normal position.

Fig. 18 is a similar view, the parts being in position to print'a subtracting sign.

Fig. 19 is a similar view, the parts being in position to overdraft.

Fig. 20 is a detail'side elevation of certain of the parts of the mechanism of Figs. 17. 18, 19; and

Fig. 21 is a detail of 17, 1s, 19.

As set forth in Ellis Patents No. 1.197.276 and N0. 1203.863, the machine is driven or. operated. either by a handle. or by an electric drive, neither of which is shown. from a shaft 01. In the accompanying drawings a link shown in Figs.

print a credit balance sign, or an I only so much of the. patented Ellis machine is shown as will afford a clear understanding of the relation of the present ill'.ii'()\(- ments thereto. hlodern cal ulating niachines, particularly thoseintendml for lu-Tri leaf ledger work, are electrically driven and controlled by a starting bar. I have, therefore, illustrated starting bar mechanism for the control of the electric drive such mechanism appearing in Figs. 8, 9 and 11.

The shaft 01 carries a piece M051 (Fig. 3) which is operated by the electric drive.

Secured to shaft Pl which is mounted in the frame and in the side plate P50 of the printing section is a crank 0160 which is operated from the piece M051 by the printing pitman 061. Carried by the shaft P1 is the paper feed lever P74.

Referring to Figs. 3, 17, 18, 19, the signal setting arm which is moved by the cams N67R and 67NR that swing the frames of the wheels of the accumulators, as shown in Ellis Patent No. 1,065,792, appears at 601?. One of the printing type sectors is shown at P54, pivoted to arm P52 at P10 and adapted to be set by link P53; the signal 65P which is pivoted to arm P52 atPlO, is operated by. link 23.55 by improved means hereinafter described, of which the signal lever 61F pivoted at 'PlOP constitutes a part.

The decimal slide, P67 is operated by a slide B53 connected to the hook P68 of the slide P67. The B53 has a button 10B and is movable over the scale B154. The decimal slide P67 appears in Figs. 3 to 9, and 11.

The lever P272 (Figs. 3, 4, 8, 9) controls the automatic turning of the platen.

A plate D50 which is secured to the left hand end of the operating shaft 01 (Figs. 1, 2) affords the means by which the motion of said shaft is utilized for the operation of the accumulators, according to the controls effected by the various controlling keys.

Such of the present improvements as relate to the controlling keys, including the subtracting key K67, the balance or total key K63 for the upper accumulator, and the sub-total key or total deposits key K64 are shown more particularly in Figs. 1, 2, and 8.

The lower accumulator is notshown in detail. This accumulator as combined with the mechanisms of Figs. 1 and 2,'is controlled only for purposes of addition and may be constructed as set forth in my application Scrial No. 510,029, filed October 24, 1921. It is to be understood, however, that the lower accumulator may be a combined adding and subtracting accumulator as disclosed in Ellis Patent No. 1,203,863 as additional mechanism could be employed so that subtraction as well as addition could be carried on in the lower accumulator in connection with the overdraft features of the present invention.

Only so much of the upper combined adding and subtracting accumulator is shown in Figs. 8. 9. 10. 11. as will afford a clear understanding of the operation of the mechanisms when an overdraft takes place, and

the relationship of this accumulator to the improved mechanisms shown in Figs. 1 and 2 by which the upper accumulator is controlled. Reference is to be had to Ellis Patent No. 1,203,863 for a detailed disclosure of the general construction and principle of the upper adding and subtracting accumulator.

The. subtraction key and subtracting meclianismreThe key used'for setting the machine so that subtraction may be performed in the upper accumulatoris shown at K67 in Fi 1 and 2, this key being, in the plresent instance, substituted for the Dr. sub-total key K67 of the lower accumulator of theEllis Patent No. 1,197,276. It is not essential, however, that the Dr. sub-total key of the lower accumulator be dispensed with. Ailatch L160 which is" actuated by spring 81L and is pivoted at D20, adapted to latch the subtraction key-K67 whenthe latter is inldepressed position. ;Pivotally connec'tedto the latch L160 at"L23L is a long set link 64L which-is provided at N18 with a pin and is provided at X. with a cam slot so fashioned and located that the set link is normally sustained by a screw pin N17 projecting from the frame B47 and on which said set link rests. When the subtraction key K67 is depressed, however, the movement of the set link 64L to the left, causes the screw pin N17 to enter the cam slot X which thereupon allows the set link to drop to the position shown in Fi 1. The shafts N1 and 1N carry the cams 67R and 67NR (Figs. 17, 18, 19) which swing the wheels of the upper and lower accumulators into and out of engagement with the addin racks or actuators, as explained in Ellis atent No. 1,203,863, and carry on their ends the cranks 65N and N65, respectively. These cranks have rollers A30 adapted to be held in the rearwardly or forwardly arranged notches A170 and 170A of scissors like latching devices comprising pieces A169 and 169A which are drawn together by springs A86 connecting them as explained in my application Serial No. 510,029 by which the accumulator is suitably held in its engaged and disengaged relation to the adding racks.

As shown in Figs. 8, 9. 11. 12, 13. the irregular shaped shift. bar N90 of Patent No. 1.203.863 is employed and on the left hand end of this bar there is secured a crank lever 69N which has a square stud D13 at its lower end and a stud N19 at its upper end. Spring 82N normally pulls the crank lever 69N in a counter-clockwise direction.

A subtracting operating hook 68N has a slot 68N bv which it is slidahly mounted on the pin N19. This hook is normally drawn rearwardly on the pin N19 by two" contractile coil springs N81 located on op and the subtracting detent N69 upwardly.

, Referring again to Figs. 1 and 2, there is pivoted on a screw L25L a subtracting cam L162 which has a cam at its right hand end with which the pin -L22L on the latch L160 normally engages, the said pin riding on the cam end of L162 and depressing said cam L162 when the subtraction key is depressed as shown in .Fig.

1. A subtracting cam lever 60L is also pivoted on the screw L25L and is connected to the subtractin spring L80 which normally holds the'left hand end ofthe subtracting cam lever 60L raised and'in Contact with a headed stud L16L on the subtractiif cam L162.

A total cam lever 58 is pivoted on screw L25L and has its left hand end abutting a pin L21L. projecting from the subtracting cam L162. The normal position of the total cam lever 58L is maintained by the engagement of the right hand cam notch thereof with pin L14L carried by the latch 56L for the sub-total or total deposits key K64, such latch and key being of the same general construction set forth in Ellis Pat ent No. 1,197,276. A spring 56L normally draws the upper. end of the latch 56L against the stem of is depressed thereof.

A hardened shoe L90 is secured by rivets 28D to the left hand end of the subtracting cam lever 60L for cooperation, when set by the keys K63, K64 and K67, with the hardened shoe D90 on the lower end of flying lever D53 which is pivotallymounted on the plate D50 at D14 and adapted to cooperate with the square studs D12, and 13D on said plate.

A total pawl L62 is pivoted on a stud 19L carried on the inner face of the subtracting cam L162, said total pawl having a pin 20L which extends underneath the subtracting cam L162. The total pawl L62 is normally held in the position shown in Figs. 1 and-2, with the pin 20L abutting the lower edge of subtracting cam L162 b the action of a spring L82 connecting said total pawl to a projecting part of the subtracting cam L162. The total pawl L62 carries on its upper end a hardened shoe L91 secured by rivets 28D.

The total or balance key K63. is held, when depressed, by a latch I 156 which is piv oted at L19L and is provided with a pin L21 adapted to be drawn against the end of the the latch .will engage the notch tions shown in Fig. 1. The ri pin L22L on the subtracting cam Ik162 cam L162 by a contractile key K64 so thatwhen the key the movement of the set total cam 58L by when the key K63 is de ressed.

Setting the acou'm, or by subtraction key.VVhen the subtraction key K67 is dethe action of spring L56 pressed, it is immediately latched in its depressed position by the latch L160 whose op-, eration results in parts ass the causes the whole system of mechanism am ciated with L162 to turn in a eiieral clockwise direction, resulting in e total cam lever 58L becoming released from the-pin L21L, the subtracting cam lever 60L to so so that its shoe L90 is against the shoe of the flying lever D53, and the total pawl L62 to become elevated so that it will be ongaged by the shoe D at the end of amine ward stroke of the shaft 01 and latn D50.

The movement of the latch L160 causes the set 64L"-to shift toward the'l ft, thereby allowing the screw guide pin N17 enter the cam slot X. This results in the set I link 64L drop from its normal position to that shown iii h ig. 1. Normally the lower 'edge of the subtracting operating hook 68N rests on the pin N18 so that said subtracting operating hook is held in elevated When, however; the set link 64L ascends, as described, the subtracting operating hook 68N is allowed toidropJ so that it is positioned for engagement y a pin 18N on the crank 65N which turns the cams not shown) that lower the wheels N50 igs. .B 9, 12, 13)hinto engagement with the adding racks of the machine at the proper time. The subtracting operating hoo 68N is, by

link 64L, thus consition.

ditioned so that it may be pulled toward the i right when the crank 65N swings to the right.

Subtracting operatz'oaag-The parts having- 1 thus been set, w en the machine is operate either by a handle or electric drive used for the purpose of turning shaft 01, the plate D50 which is normally in the position shown in Fig. 1 is turned to the right and then re verses its motion and resumes the position shown in Fig. 1. Before the return of the plate D50 to the normal position of F ig. 1, the subtraction key K67 becomes restored and the subtracting cam L162 and subtracting cam lever 60L and total cam lever 58L all resume their normal position.

In the Ellis machine set forth in Patents No. 1,197,276 and No. 1,203,863 when an operation of addition is to be performed, the adding racks or actuators R50 (Figs. 12, 13) advance, during the operation of the machine, as far as allowed by the setting of the numeral keys before the shafts N 1, IN, are turned (according to which accumulator is being used) for the purpose of engaging the wheels N50 (Figs. 8, 9, 12, 13) with said racks. This action occurs, in an adding operation, when the plate D50 has moved through an angle of about The wheels N remain in engagement with the racks R50 until the racks have returned to normal position, such return of the racks turning the adding wheels N50 according to the extent oftravel of said racks.

\Yhen an operation of subtraction is to be performed, however, as the number is to be immediately deducted from any number set up on the wheels N50 during a previous operation of the machine, it becomes necessary to cause the wheels N50 to engage the racks R50 before said racks move and to disen age the wheels N50 from the racks before the racks start to return to their normal osition. In a subtracting operation, thereore, it is necessary to move the upper crank 65N to the right from the position shown in Fig. 1 to its other position before theracks R50 have started to move.

The subtraction key having been set and the parts being in the position shown in Fig. 1, when the machine is operated, the swinging of the plate D50 in a clockwise direction results in a temporary arrest of the flying lever D53 because its lower end is temporarily blocked by the shoe L90 on the subtracting cam lever L. This results in lever D53 pulling upon link D56 which connects it to the crank N of the adding and subtracting accumulator, causing the shaft N1 to be turned and the frame 51N, 56N, which carries the shaft N2 to be moved and wheels X50 then mesh with the racks R50 before the racks start. to move. The roller A30 on crank 65K is drawn into the notches 170A so that the wheels N50 are retained in engagement with the racks R50. The movement of the connecting link D56 to the right from the position shown in Fig. 1 also results in the pin 18X pulling upon the subtraction operating hook 08X which, through the spring connections N81, pulls upon the pin N19 and thus turns the crank GQN and the shift bar N90, bringing the shift bar N00 to the position shown in Fig. 12, which is the subtracting position.

The first part of the movement of the plate D50 releases the restoring lever D67, allowing the spring N82 to snap the subtracting detent N60 upwardly so that the notch N69 thereof engages the square stud D13 on crank (EON.

During its clockwise movement. the plate D50 drags the lever end of flying lever D53 past the shoe L00 on the sulistracting cam lever 60L so that after the accumulator has been set for substraction and the wheels N50 engaged with the racks R50, the said flying lever D53 simply turns idly on its pivot D14 and exerts no further action on the crank 05h and hook (BEN. The lower end of the lever D53 is finally drawn across the shoe L91 of the total pawl L62 and as this pawl is ac-' tuated by spring L82, it is slightly depressed, allowing the flying lever D55 to finally abut the shoe L91.

On the return stroke of the shaft 01, the plate D50 is turned in a counter-clockwise direction. The return movement of the plate D50 causes the lower end of lever D53 to press against the shoe L91 of the total pawl L62. The pressure being almost in a direct line with the pivot 19L of the total pawl L62,i. e., almost directly on a dead center, there is no tendency for the lever D53 to depress the total pawl L62 but, on the core trary, the total pawl L62 constitutes a solid abutment to temporarily resist the return of the lever D53 so that pressure is applied through lever D53 and connecting link D56 to the crank 65N, causing said crank to be returned to its normal position at the beginning of the return stroke of the plate D50, thereby resulting in the turning of shaft N1. and the raising of the frame 51N, 56N, (Figs. 8, 12 and 13) and disengagement of the wheels N50 from the racks R50 before the racks start to return to normal position. \Vhen the plate D50 returns to its normal position it again engages the restoring lever D67 andcauses the pin D13D to elevate the right hand end of the substracting detent N69 andto withdraw the notch N69 from engagement with the stud D13.

While no disclosure is given of means for latching down the substraction key K67 for a series of repeated substractions without requiring the operator to hold his linger on said key, such latching means may be provided, if desired. In the construction disclosed, the substraction key K67 will instantly rise when the latch L160 is moved in a counter-clockwise direction. This action automatically occurs on the return stroke of the shaft 01 and plate D50.

Means, such as set forth in my application Serial No. 598155, may be provided for automatically releasing the latches 67L, 68L, L100 for the keys K03, K64, K67 on the return stroke of the plate D50; and means for releasing them by depressing the error key, may be used, as disclosed in that application.

The releasin movement of the latch L160 in a counter-clockwise direction by means such as previously explained. causes the set link 64L to be drawn toward the right, out of the position shown in Fig. 1, whereupon the cam edges of the slot X cause the set link to ride on the pin NIT and resume its normal position. The rising of the set link 64L causes its pin N18 to elevate the subtracting hook (SSN from the subtracting position to the adding position where it will remain as long as the subtraction key K67 remains in elevated position so that addition may be performed in the upper accumulator llii by depressing the proper controlling key provided in the Ellis machine.

lVhen the plate D50 assumes its normal position, its engagement with the restoring lever D67 results in disengagement of the detent N69 from the lever 69N and the shift 7 tracting cam lever 60L then remaining in the position shown in Fig. l by reason of the cooperation of pin L22L of latch L160 with subtracting cam L162. When the subtracting key is thus held down, at a time just prior to the plate D assuming its normal position on the return stroke, the lower end of the flying lever D53 strikes'the upper side of the shoe L90 on the subtracting cam lever L but as the left hand end of said lever is held in raised position by spring L80, the return of the flying lever D53 to normal positionmerely slightly depresses the left hand end of cam lever 60L and then passes beyond it, finally assuming the position shown in Fig. 1.

Release of numeral keys-The numeral keys (not shown) which are fully disclosed as to construction and operation in Ellis Patent No. 1,197,276 are released, so that ,they may spring up to normal position, by

means substantially similar to those shown in Ellis Patent No. 1,203,863. When addition or subtraction is being performed, the

numeral keys are released on the return stroke of the shaft 01 and plate D50.

When a total or balance, or sub-total or total of deposits, is to be taken, the numeral keys are released during the first 15 of the forward stroke of the shaft 01 and plate D50. This is accomplished from the latches L56, 56L when the key or keys K63, K64 are set, the total cam 58L then being shifted and, in turn, setting the parts L162, 60L and bringing about operations as explained in Serial No. 598,155.

The adding or debit accuwmZat0r.In the drawings I have shown the operating mechanism for the lower or Dr accumulator in Figs. 1 and 2. This accumulator may be of the construction shown in my application Serial No. 510,029, filed October 24, 1921. As previously explained the lower accumulator may be a combined adding and subtracting accumulator such as set forth in the Ellis Patent No. 1,203,863. In the present description and drawings I have not shown the controlling keys for the lower accumulator nor will specific description be given of the means by which the adding crank N of the lower accumulator is rocked to turn the shaft 1N which carries the cams 67NR that swing the lower accumulator wheels into mesh with the lower sides of the racks R50 but the manner of operating said accumulator will be clear from the disclosures of the Ellis Patent N 0. 1,197,- 276 and the mechanism shown in Fig. 46 of that patent and also Fig. 3 of Ellis Patent No. 1,197,278. It is only necessary, for the purposes of the present. invention to state thatthe rocking plate D50 operates the flying lever D54, connection D57 to the pin 18D of the crank N65 and that there is a piece D52 similar to the piece D51, said parts being located back ofthe plate D50 and serving, whenflthe proper keys, not shown, are set, to enable the lower accumulator to be used for purposes of addition.

Assuming, therefore, that the lower accumulator is used as explained, it is possible with the present invention to subtract the total accumulation of the lower accumulator from the amount added in the upper or Cr. accumulator.

Subtracting the amount in the debit accumulator from the amount in the credit accumuZator.-'For carrying on a subtracting operation, it is immaterial as to what means is used to limit the travel of the racks R50. If the lower-.or Dr. accumulator is engaged with the racks R50 for the purpose of taking a total while the Cr. accumulator is engaged with saidrac'ks for the purpose of carrying on a subtracting operation, it is evident that the wheels of the Dr. accumulator will limit the travel of the racks R50 and thatthe precise extent of travel of the racks will be represented by a corresponding subtractin operation which will deduct the amount rom what is contained in the Cr. accumulator.

Furthermore, if both of the accumulators are constructed. for both addition and subtraction, it will be immaterial as to which accumulator is set for the taking of a total and which is set for subtraction.

The pieceD58 which is shown in Figs. 46 and 47 of Ellis Patent No. 1,197,276, and Fig. 3 of. Ellis Patent N 0. 1,197,278 has a pin D21 which is received inthe forked end of the piece D66 which is connected to the end of the restoring lever D67, said pin D21 cooperating with. the angled piece D51. The pin D21 performs an additional function aving to do with the overdraft features of the invention hereinafter described, its purpose being to prevent further addition when an overdraft has occurred. The manner in which this is accomplished will be explained hereinafter.

Overdraft mechanism and its 0peratz'0n. lVhen the total of the items subtracted from the upper accumulator exceeds the total of the items added on said accumulator, a condition occurs causing the mechanism that coordinates with the total or balance keys to become inoperative, thus indicating to the 

